Thomas davies nicholls



:Nrrn STATES PATENT m res,

THOMAS DAVIES NICHOLLS, O-F SKEWEN, NEAR, NEATH, AND CHRISTOPHER JAMES,OF SWANSEA, ENGLAND.

METHOD, OF RE F'INJNG. COPPER.

SPECIFICATION forming part-f: Letters: Patent No. 532,809, dated January22,1895.

Application filed June 18,1891- Serial No. 396,715. (No-specimens.)Patented in England November 21, 1890 No. 18,898 1 in Spain July- 9,1891, ITO-121214;; inItaly July 14, 1891, XXV, 29.950, LVIII, 450,- inNewfoundland August 10.18.91 in France September 30, 18-91, No-2'1'45025, and in UapeofG'ood HopeFebruaryZd, 13-92, No 74L To all whom,it may concern.-

Be it known that we, THoMAs DAVIES NICH- OLLS, residing at Gl'an-MorVillas,Skewen,. near Neath, and CHRISTOPHER JAMES, of Ida Villa,Swansea, in the county of Glamorgan,

England, have invented an Improved Method of Refining Copper, of whichthe following is a specification.

The invention has been patented in Great to Britain, No. 18,898, datedNovember 21', 1890; in France, No. 214,025, dated September 30, 1891; inItaly, XXV, 29,950, LVIIL450, dated July 14, 1891; in Spain, No. 12,214,dated July 9, 1891; in Newfoundland August 10, 1891, 15 and in theColony of the Cape of Good. Hope,

No. 741, dated February 27, 1892;

This invention. relates to an improved;

method of producing refined copper from copper matte, regulus orprecipitate and the operations entailed therein are conducted asfollows; In the ordinary methods now in use copper matte or regulus,consisting principally of copper and sulphur, is piled, in as: largepieces as practicable, in a roaster fur- 2 5 mace, and slowly sweateddown while exposed to a current ofair let in through-the-side door ofthe fnrnace,-through air holes or plugs, orthrough passages arrangedthrough the fire by the workman; thus burning off the o sulphur nearly,and leaving the copper, after' melting and skimming to be tapped out aspimple or blister copper. This operation takes seldom less, than twentyfourhours for the production of three tons of pimple 5 or blister copperfrom matte-of seventyfive or seventy-six per cent. while a large amountof copper passes into the roaster slags, which have to be resmelted. Theblister or pimple copper, thus made, is then filled 0 as pigs into arefinery furnace and again sweated down under an oxidizing flame,

skimmed, refined and brought to the required pitch, and finally ladedinto cakes, ingots, au-

odes, &c.

In the new method proposed herein, we avoid the expensive and wastefultwo operations of roasting and melting, first in a roaster and again ina refinery furnace by substituting. a cal'cinati'on of'alportion only ofthe matte, then mixing this calcined portion with a suitable portion ofraw (uncalcined) matte. Thisimixtu-re isthen charged d-i'rectl'yinto arefinery furnace, and melted atonc'e into impure metallic copper orblister icopper containing about. ninety-seven and one-half percent. ofcopper with sulphu rand traces of other metallic impurities which isbrittle and unmalleable. It is then refined in the usual way in thehearthof' the same refinery furnace in which the calcined and raw 6omatte (of say seventy-six tose-ven ty-eigh't per cent. of copper) hasbeen sine'l'ted. This usual way of refiningis. by oxidation of theliquid. metal in the hearth: while it is being. 'fiap'ped orstirred bysnita-ble'hand hoes or flaps until all the sulphurandanytraces-of' 1iron, nickel,.arsenic, and antimony have been i oxidized and removed"vas slag, volatile bodies being vol'atilized and any excess of oxidationlis then removed by po-ling with timber 7o 2 poles. The metal is thusreduced to refined icopper of 99.6- or one hundred per cent. of jicopperby the" continuous process in the'one furnace and is malleable and ofgreat tenacity, lit for the market, and. is, then formed as requiredinto cakes, ingots, anodes, &c.

We: find in practicethat the best, and most @econom-ical matte forourprocess is one of iaboutseventy-six to seventy-eight per cent.@of'copper, matte of this pitch containing but llittle iron, and somaking very little slag in itherefinery furnace; The whole of this matteis crushed through athree-eigh-ths inch screen (or smaller it convenientthough when rich matte is treated fine dust is wasteful).

A portion of our matte or regulus we calcine in reverberatory calcinersor revolving cylinder calciners or any calciner at present in or-.dinary use. The calcination of this portion of matte is so conducteduntil itis dead and mixed with such a portion of raw matte as willsuffice (when melted together) to render all the copper in both portionsas metallic copper of a pitch similar to the blister copper from theordinary roaster. Both 5 portions, so mixed, form the refinery charge.

The reactions which insure the success of this method of working may bedescribed as follows: Copper matte of the preferred pitch consistsessentially of copper sulphide (011 8). This when calcined perfectlywould be changed to copper oxide (0110) of equal weight with the coppersulphide operated on. This copper oxide (G110) upon being melted withits own weight of raw copper matte (Ou S) produces metallic Cu from bothportions with the evolution of nearly all the sulphur and oxygen assulphur gas, as expressed by the well known formula:

In practice we find that to perfectly calcine the portion of matte sotreated is tedious and expensive, the calcination of the copper sulphideto red oxide of copper (Ou O) being comparatively easy while the furthercalcination of this red oxide to black oxide (CuO) requires so muchlonger time and greater heat, that although the black oxide will carryits own weight of raw matte in the refinery charge, it is cheaper toonly so far calcine our matte that upon trial it is found that about twoparts of calcined matte and one part of raw matte will, upon meltingrender all the copper as blister copper with very little slag.

We claim, that by treating only about two thirds of our matte in acalciner, and then melting the total quantity in a refineryfurnace withthe immediate production of metallic copper, which is at once refined inthe hearth of the same furnace in which the mixed calcined and raw mattehas been smelted without remelting, good copper is produced at far lessdirect cost than by the ordinary roasting and refining processes; thatmore copper is obtained in a salable form and far less slags producedthan by the roasting, melting and skimming, first in a roaster, andagain in a refinery furnace with the production of heavy slags in eachoperation.

In our method of working, we find that all volatile impurities (arsenic,antimony, bismuth, &c.) are more freely got rid of than in the roastingprocess, partly in the thorough calcination of the calcined portion, andagain during the evolution of the large volume of sulphur gas, given offon melting the mixed charge in the refinery, aided by the intensechemical heat developed by there action set up by the combining of themelting oxide and suphide.

The non volatile impurities (iron, nickel, &c.) are got rid of, to atleast as great an extent as by the roasting process, by a judiciousmixing of the proportions of calcined and raw products, so as to obtaina slag of melted oxide, in more or less quantity upon the liquid bath ofmetallic copper in the hearth of the furnace. Such non volatileimpurities are naturally collected in this slag, and are skimmed offwith it, a suitable flux (such as sand, lime, niter, 850.) being addedto the refinery charge when very impure matte is operated on. Althoughmatte of seventysix to seventy-eight per cent. of copper is preferred,correspondingly good results are obtained from poorer mattes.

The actual cost of practically working this method has been found to beless than half the cost of the ordinary method, as carried out in wellconducted works using the old method.

Although we use by preference matte of seventy-six to seventy-eight percent. of copper and a calcined portion of the same or other matte, ourinvention applies with correspondingly good results to all matte of fromforty-five to eighty per cent of copper.

Having fully described our invention, what we claim, and desire tosecure by Letters Patent, is-

The herein described method of producing refined copper from coppermatte, consisting in crushing the matte, calcining a proportion of thecrushed matte, mixing therewith a suitable portion of uncalcined matte,charging said mixture directly into a refinery furnace and melting thesame and finally refining the product in the same furnace on the hearththereof whereby the material is thus reduced to refined copper by acontinuous process in the same furnace, substantially as described.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

THOMAS DAVIES NICHOLLS. CHRISTOPHER JAMES. Witnesses:

EDWIN GEORGE PROMEROF, DAVID RICHARD BOWLER.

